Synergistic interaction of weak cation exchange resin and magnesium oxide

ABSTRACT

The present invention relates to methods, apparatuses, and systems for treating water. The methods, apparatuses and systems reduce scaling associated with solubilized water hardness using a sequence of water treatment agents, including a first threshold agent shedding weak cation exchange resin and a second magnesium compound conversion agent water treatment. The system or apparatus and methods according to the invention provide synergistic reduction of hard water scaling and elimination of cementing on the insoluble magnesium compound.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 13/206,879filed Aug. 10, 2011, which claims priority and is entitled “SynergisticInteraction of Weak Cation Exchange Resin and Magnesium Oxide”. Theentire contents of this patent application is hereby expresslyincorporated herein by reference including, without limitation, thespecification, claims, and abstract, as well as any figures, tables, ordrawings thereof.

FIELD OF THE INVENTION

The invention relates to a system or apparatus and methods for treatingan aqueous system, such as a water source or stream (i.e. watertreatment). The invention relates to use of a threshold agent sheddingweak cation exchange resin followed by use of magnesium oxide for thetreatment of an aqueous system. In particular, the system or apparatusand methods according to the invention provide synergistic reduction ofhard water scaling and reduced or eliminated cementing of the magnesiumcompound through the combined, sequential use of a first treatment usingan exhausted divalent cation exchange resin followed by a secondtreatment using a water insoluble magnesium compound, such as amagnesium oxide. Methods of cleaning using the treated aqueous systemare also disclosed and beneficially provide reduced water scaling ontreated surfaces.

BACKGROUND OF THE INVENTION

Water hardness has numerous deleterious effects in various systems. Forexample, when hard water alone, or in conjunction with cleaningcompositions, contacts a surface, it can cause precipitation of hardwater scale on the contacted surface. Hard water is also known to reducethe efficacy of detergents. In general, hard water refers to waterhaving a total level of calcium and magnesium ions in excess of about100 ppm expressed in units of ppm calcium carbonate. Often, the molarratio of calcium to magnesium in hard water is about 2:1 or about 3:1.Although most locations have hard water, water hardness tends to varyfrom one location to another.

Water hardness has been addressed in a number of ways. Most cleaningproducts contain one or more ingredients whose presence is intended tooffset the effects of hard water. Examples include phosphorus-containingand especially phosphate-containing acids (or more commonly saltsthereof, including sodium or potassium salts) such as sodiumtripolyphosphate (STPP) and sodium etidronate. Other such ingredientsinclude threshold agents, such as aminocarboxylates (for example,ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaaceticacid (DTPA), nitrilotriacetic acid (NTA) and their salts) andpolycarboxylates (for example, polyacrylates, polymethacrylates andolefin/maleic acid copolymers). However, there may be difficulties inincluding such ingredients in cleaning products, as several of theseingredients have been banned in various states or subjected toregulatory amount limitations due to environmental concerns (e.g.,eutrophication and biodegradability) or other factors, and some are verycostly.

Another method currently used to soften water is via ion exchange, e.g.,by adding sodium to the water to exchange the calcium and magnesium ionsin the water with sodium associated with a resin bed (or the like) in awater softening unit. The calcium and magnesium adhere to a resin in thesoftener. When the resin becomes saturated it is necessary to regenerateit using large amounts of sodium chloride dissolved in water. The sodiumdisplaces the calcium and magnesium, which is flushed out in a brinysolution along with the chloride from the added sodium chloride. Whenwater softeners regenerate they produce a waste stream that containssignificant amounts of chloride, creating a burden on the system, e.g.,sewer system, in which they are disposed of, including a multitude ofdownstream water re-use applications like potable water usages andagriculture.

The use of an insoluble magnesium compound, such as a magnesium oxidebed, is used to prevent or reduce scaling (e.g. hard water scaling,silica scaling). Use of magnesium is believed to cause calcium carbonatein hard water to crystallize into a non-scaling form rather thancrystals of calcite causing hard water scale is a further method.However, certain performance difficulties often impede its ability tocontrol water hardness. In some instances, the magnesium oxide bed islimited by its slow “cementing.” “Cementing” is a phenomenon in whichthe discrete particles of magnesium oxide become tightly bound together,such as through the bridging of the magnesium oxide granules by calciumcarbonate. This reduces the efficiency of the magnesium oxide, creatinga non-fluidizable bed that is no longer free-flowing. The cementingeffect makes it very difficult to remove the granules from the bed,cartridge or other types of containers, causing deleterious effects tothe system for treating hard water as it eventually forms into anintractable block during the course of use and limiting commercialviability. A further method of counteracting water hardness is to usechelating agents or sequestrants which are intended to be mixed withhard water in an amount sufficient to handle the hardness. However, inmany instances the water hardness exceeds the capacity of the chelant orthreshold agent added to the composition.

In yet a further method of counteracting water hardness, a cationexchange resin with a divalent ion exchange capacity fully exhausted canbe used to form and shed a threshold agent in situ into a system.However control over the quantity of threshold agent shed can bedifficult.

Accordingly, it is an objective of the claimed invention to develop amethod for reducing hard water scaling superior to the use of watertreatment systems using exhausted cation exchange resins or magnesiumoxide beds, cartridges or other types of containers alone. A furtherobject of the invention is a system for eliminating hard water scalingfor use in various cleaning applications.

A further object of the invention is a system and methods foreliminating the cementing of magnesium oxide beds, cartridges or othertypes of containers.

BRIEF SUMMARY OF THE INVENTION

In an embodiment, the present invention provides methods for reducinghard water scaling in a water source. In one aspect, the methodscomprise contacting a water source with a first ionic resin watertreatment agent; contacting the treated water source with a second metaloxide and/or hydroxide compound water treatment agent, wherein the firstwater treatment agent sheds a threshold agent, and wherein thesolubilized water hardness in the treated water source does not resultin hard water scaling

According to embodiments of the invention, the ionic resin and metaloxide and/or hydroxide compound are housed within one or more treatmentreservoirs. The and metal oxide and/or hydroxide compound is preferablyselected from the group consisting of metal oxides, metal hydroxides,and combinations thereof, more specifically the conversion agent isselected from the group consisting of magnesium oxide, magnesiumhydroxide, aluminum oxide, aluminum hydroxide, titanium oxide, titaniumhydroxide, and combinations thereof. In a certain embodiment thecompounds are free of aluminum and/or zinc. In a further aspect, themetal oxide and/or hydroxide compound is insoluble in water and iscontained in a column, cartridge or other holding container and thecolumn is agitated by a method selected from the group consisting of theflow of water through the column, by fluidization, mechanical agitation,high flow backwash, recirculation, and combinations thereof.

According to further embodiments, the ionic resin is a weak cationexchange resin. In a further aspect, the cation exchange resin isexhausted and sheds a threshold agent that is an acrylic acid polymer, amethacrylic acid polymer or combinations thereof.

In a further embodiment, the present invention provides an apparatus orsystem for treating a water source for use in a cleaning application. Inone aspect, the apparatus or system may comprise: (a) an inlet forproviding a water source to a first treatment reservoir; (b) one or moretreatment reservoirs housing (1) a first water treatment agentconsisting of a substantially water insoluble ionic resin loaded with aplurality of one or more multivalent cations, followed by (2) a secondwater treatment agent consisting of a metal oxide and/or hydroxidecompound; (c) an outlet for providing treated water from the one or moretreatment reservoirs; and (d) a treated water delivery line forproviding the treated water to a cleaning application.

In further aspects, there is no filter between the first and secondtreatment reservoir and/or the outlet and the treated water deliveryline. Still further, in another aspect, the one or more of the treatmentreservoirs comprise a portable, removable cartridge.

In a further embodiment, the present invention provides methods of usinga treated water source to clean an article. In an aspect, the methodscomprise treating a water source with a first ionic resin watertreatment agent comprising a substantially water insoluble ionicexchange resin; treating the water source with a second metal oxideand/or hydroxide compound water treatment agent, wherein the treatingsteps comprise running the water over a solid source of first the ionicresin and running the water over the second metal oxide and/or hydroxidecompound, and wherein the solubilized hardness of the water is increasedcompared to the initial solubilized hardness of the water source; andcontacting an article with the treated water or a use solution formed bycombining the treated water with an additional cleaning agent (e.g.detergent) such that the article is cleaned without causing hard waterscaling on the article.

While multiple embodiments are disclosed, still other embodiments of thepresent invention will become apparent to those skilled in the art fromthe following detailed description, which shows and describesillustrative embodiments of the invention. Accordingly, the drawings anddetailed description are to be regarded as illustrative in nature andnot restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the effect of elution order on scale mitigation of MgO anda weak cation exchange resin according to an embodiment of theinvention.

FIG. 2 shows a schematic of a treatment reservoir according to anembodiment of the invention.

Various embodiments of the present invention will be described in detailwith reference to the drawings, wherein like reference numeralsrepresent like parts throughout the several views. Reference to variousembodiments does not limit the scope of the invention. Figuresrepresented herein are not limitations to the various embodimentsaccording to the invention and are presented for exemplary illustrationof the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention relates to systems, apparatus and methods forreducing hard water scaling. In particular, the present inventionrelates to water treatment for reducing scale formation and reducingand/or eliminating cementing of a magnesium oxide bed, cartridge orother type of container used for the water treatment according to theinvention. The present invention also relates to methods of employingtreated water, for example, in cleaning processes. The systems,apparatus and methods of the present invention have many advantages overexisting techniques. For example, according to the invention, certainsequential combinations of a resin and an insoluble magnesium compoundinteract synergistically, providing hard water scale inhibition superiorto either technology alone. In addition, the present invention mitigatesthe concern and deleterious effects of the magnesium oxide bed,cartridge or other type of container cementing.

The water treated in accordance with the methods of the presentinvention has many beneficial effects, including, but not limited to,reduction of scale and soiling in areas where hard water can causesoiling, protecting equipment, e.g., industrial equipment, from scalebuild up, protecting water treatment equipment (e.g., magnesiumcompounds in beds, resins and other types of containers) from thedeleterious effects of cementing, increased cleaning efficacy when usedwith conventional detersive compositions, and reducing the need forspecific chemistries, e.g., those containing threshold agents, chelatingagents, or sequestrants, or phosphorous, in downstream cleaningprocesses.

The embodiments of this invention are not limited to particular systems,apparatus and methods, which can vary and are understood by skilledartisans. It is further to be understood that all terminology usedherein is for the purpose of describing particular embodiments only, andis not intended to be limiting in any manner or scope. For example, asused in this specification and the appended claims, the singular forms“a,” “an” and “the” can include plural referents unless the contentclearly indicates otherwise. Further, all units, prefixes, and symbolsmay be denoted in its SI accepted form. Numeric ranges recited withinthe specification are inclusive of the numbers defining the range andinclude each integer within the defined range.

So that the present invention may be more readily understood, certainterms are first defined. Unless defined otherwise, all technical andscientific terms used herein have the same meaning as commonlyunderstood by one of ordinary skill in the art to which embodiments ofthe invention pertain. Many methods and materials similar, modified, orequivalent to those described herein can be used in the practice of theembodiments of the present invention without undue experimentation, thepreferred materials and methods are described herein. In describing andclaiming the embodiments of the present invention, the followingterminology will be used in accordance with the definitions set outbelow.

The term “about,” as used herein, refers to variation in the numericalquantity that can occur, for example, through typical measuring andliquid handling procedures used for making concentrates or use solutionsin the real world; through inadvertent error in these procedures;through differences in the manufacture, source, or purity of theingredients used to make the compositions or carry out the methods; andthe like. The term “about” also encompasses amounts that differ due todifferent equilibrium conditions for a composition resulting from aparticular initial mixture. Whether or not modified by the term “about”,the claims include equivalents to the quantities refers to variation inthe numerical quantity that can occur.

As used herein, the term “builder” refers to a compound that is achelating agent or sequestering agent. As used herein, the terms“builder,” “chelating agent,” and “sequestrant” are synonymous. Theterms “chelating agent” and “sequestrant,” as used herein, refer to acompound that forms a complex (soluble or not) with water hardness ions(from the wash water, soil and substrates being washed) in a specificmolar ratio. Chelating agents that can form a water soluble complexinclude sodium tripolyphosphate, EDTA, DTPA, NTA, citrate, and the like.Sequestrants that can form an insoluble complex include sodiumtriphosphate, zeolite A, and the like. As used herein, the terms“builder,” “chelating agent,” and “sequestrant” are synonymous.

The term “cleaning,” as used herein, means to perform or aid in soilremoval, bleaching, microbial population reduction, or combinationthereof.

As used herein, the term “conversion agent” refers to a species thatcauses solubilized calcium in water to substantially precipitate fromsolution as calcium carbonate in a form which is thought to be a morethermodynamically unfavorable form. Although not intending to limit thescope of the invention, according to one theory of the invention, aconversion agent may have a mechanism of action that causesprecipitation of solubilized calcium in the crystal form of aragoniterather than as the thermodynamically favorable crystal form calcite.According to this non-limiting theory of an aspect of the invention,aragonite is a fragile crystal which doesn't bind well to surfaces anddoesn't form hard water scale while calcite is a more robust crystalwhich binds tightly to surfaces, forming a hard water scale that's notseen with aragonite. An example of a conversion agent according to theinvention is the magnesium compound, such as a magnesium oxide bed.

As used herein, the term “free of” or “substantially free of” refers toa composition, mixture, or ingredients that does not contain aparticular agent or compound or to which only a limited amount of suchagent or compound has been added. For example, substantially free of,according to an embodiment of the invention, includes an amount of theparticular agent or compound less than about 5 wt %. In someembodiments, such an amount of a particular agent or compound is lessthan about 2 wt-%. In other embodiments, such an amount of a particularagent or compound is less than about 0.5 wt-%. According to a furtherembodiment, free of, refers to the lack of the particular agent orcompound in a composition. According to embodiments of the invention,the conversion agent is free of aluminum and/or free of zinc.

As used herein, the term “hard surface” includes showers, sinks,toilets, bathtubs, countertops, windows, mirrors, transportationvehicles, floors, and the like.

As used herein, the terms “magnesium oxide bed,” “magnesium oxidecartridge,” or the like, refer to any type of a magnesium oxide watertreatment system employing a bed, cartridge, or other type of containeras one skilled in the art will ascertain. These terms are not intendedto limit the structure of the magnesium oxide treatment system accordingto the invention and are used merely as exemplary descriptors ofsuitable structures, others of which one of skill in the art willascertain.

As used herein, the term “solubilized water hardness” refers to hardnessminerals dissolved in ionic form in an aqueous system or source, i.e.,Ca⁺⁺ and Mg⁺⁺. Solubilized water hardness does not refer to hardnessions when they are in a precipitated state, i.e., when the solubilitylimit of the various compounds of calcium and magnesium in water isexceeded and those compounds precipitate as various salts such as, forexample, calcium carbonate and magnesium carbonate. As used herein, theterm “water soluble” refers to a compound that can be dissolved in waterat a concentration of more than 1 wt-%.

The term “threshold agent,” as used herein, refers to a compound thatinhibits crystallization of water hardness ions from solution, but thatneed not form a specific complex with the water hardness ion. Thisdistinguishes a threshold agent from a conversion agent, chelating agentor sequestrant as disclosed herein. Threshold agents are capable ofmaintaining hardness ions in solution beyond its normal precipitationconcentration. See e.g., U.S. Pat. No. 5,547,612. Threshold agents mayinclude, for example and without limitation, polycarboxylates, such aspolyacrylates, polymethacrylates, olefin/maleic copolymers,olefin/acrylate copolymers and the like. According to the invention athreshold agent is shed from an exhausted resin according to theinvention. According to an embodiment of the invention, a the exhaustedionic resin sheds a threshold agent, which as understood by a skilledartisan, interferes with the crystallization of calcium carbonate andreduces the ability to form a crystal. The term “water,” as used herein,refers to potable water as obtained from a municipal or private watersystem, e.g., a public water supply or a well. The water can be hardwater, city water, well water, water supplied by a municipal watersystem, water supplied by a private water system, treated water, orwater directly from the system or well. In an embodiment, the presentmethod employs water that wasn't treated with a polymeric water softenerbed such as in use today and which requires periodic regeneration withsodium chloride to work. In general, “hard water” refers to water havinga level of calcium and magnesium ions in excess of about 100 ppm or 17grains. Often, the molar ratio of calcium to magnesium in hard water isabout 2:1 or about 3:1. Although most locations have hard water, waterhardness tends to vary from one location to another.

The term “water soluble” refers to a compound that can be dissolved inwater at a concentration of more than 1 wt-%. The terms “slightlysoluble” or “slightly water soluble” refer to a compound that can bedissolved in water only to a concentration of 0.1 to 1.0 wt-%. The term“water insoluble” refers to a compound that can be dissolved in wateronly to a concentration of less than 0.1 wt-%.

The term “weight percent,” “wt-%,” “percent by weight,” “% by weight,”and variations thereof, as used herein, refer to the concentration of asubstance as the weight of that substance divided by the total weight ofthe composition and multiplied by 100. It is understood that, as usedhere, “percent,” “%,” and the like are intended to be synonymous with“weight percent,” “wt-%,” etc.

The methods, systems and apparatuses of the present invention caninclude, consist essentially of, or consist of the component andingredients of the present invention as well as other ingredientsdescribed herein. As used herein, “consisting essentially of” means thatthe methods, systems, apparatuses and compositions may includeadditional steps, components or ingredients, but only if the additionalsteps, components or ingredients do not materially alter the basic andnovel characteristics of the claimed methods, systems, apparatuses, andcompositions.

It should also be noted that, as used in this specification and theappended claims, the term “configured” describes a system, apparatus, orother structure that is constructed or configured to perform aparticular task or adopt a particular configuration. The term“configured” can be used interchangeably with other similar phrases suchas arranged and configured, constructed and arranged, adapted andconfigured, adapted, constructed, manufactured and arranged, and thelike.

According to an embodiment of the invention there is a synergisticeffect of combined used of a water treatment system sequentiallyemploying a weak cation exchange resin shedding threshold agent followedby a magnesium oxide bed, cartridge or other type of container for theconversion of hard water scale into non-scaling hard water. According tothe invention it is unexpected that the combination of athreshold-shedding resin with a conversion agent (e.g. magnesium oxidebed, resin or other type of structure) provides synergistic efficacy inreducing hard water scaling. This is counterintuitive as the thresholdagent and conversion agent would be expected to interfere with theother's mode of action.

Reducing Scaling Caused by Water Hardness in Water Sources

In some aspects, the apparatuses, systems and methods of the presentinvention are used to treat a water source such that the solubilizedwater hardness does not cause scaling on a surface treated with thewater source. The present invention surprisingly results in a watersource that does not have a reduced solubilized water hardness.According to an embodiment of the invention, the water hardness (e.g.measured by ppm of calcium and magnesium ions and/or grains) in atreated water source is increased without causing scaling on a treatedsurface.

The water source treated according to the invention may be any source ofwater having a hardness that would be benefited by treatment inaccordance with the methods of the present invention. Exemplary watersources suitable for treatment using the methods of the presentinvention include, but are not limited to, ordinary tap water such aswater from a municipal water source, or private water system, e.g., apublic water supply or a well. The water can be city water, well water,water supplied by a municipal water system, water supplied by a privatewater system, and/or water directly from the system or well. In someembodiments, the water source is not an industrial process water, e.g.,water produced from a bitumen recovery operation. In other embodiments,the water source is not a waste water stream.

The apparatus, systems and methods of the present invention includetreating a water source such that the solubilized hardness does notcause and/or reduces the scaling on a treated surface. In some aspects,the solubilized hardness of the water is increased and does not causeand/or reduces the scaling on a treated surface. In some aspects, thepresent invention provides methods for reducing or inhibiting scaleformation in an aqueous system.

In some embodiments, an aqueous system, i.e., a water source, iscontacted sequentially with two water treatment agents—a first exhaustedionic resin capable of shedding a conversion agent (either bound orunbound), followed by a second insoluble magnesium compound. Withoutwishing to be bound by any particular theory, it is thought that thesequential use of the water treatment agents first cause the shedding ofthreshold agents into a water source as a result of the exhausted ionicresin. One theory of the invention is that the threshold agent shed bythe exhausted ionic resin cleans off (i.e. solubilizes) the remainingsolubilized calcium water hardness ions from the magnesium oxide bed.The removal of the calcium water hardness ions from the magnesium oxidebed prevents the deleterious effects of cementing on the magnesiumcompound.

A further non-limiting theory of the invention is that the insolublemagnesium oxide may cause the water hardness to substantiallyprecipitate via an interfacial reaction from solution as calciumcarbonate in the thermodynamically unfavorable crystal form aragoniterather than as the thermodynamically favorable crystal form calcite. Theresultant crystals are very small in size, are inert and non-reactive,and do not stick to surfaces. For example, aragonite crystals formedaccording to embodiments of the invention may be between approximately10 nm and 1000 nm in size. Because it is inert and small in size, theprecipitated calcium carbonate does not need to be filtered or removedfrom the treated water. Rather, the treated water containing theprecipitated crystals of calcium carbonate can be used for anydownstream application.

According to a still further non-limiting theory of the invention, thewater hardness may be re-dissolved into the treated water source,causing an apparent increase in total solubilized water hardness (i.e.ppm of calcium and magnesium ions and/or measured grains). Without beinglimited to a particular theory of the invention, contacting water withthe sequential water treatment agents of the present invention reducesthe scaling of surfaces contacted by the treated water according to theinvention, and leads to a reduction and/or elimination of cementing onethe magnesium oxide bed, cartridge or other types of containers.

The methods of the present invention are especially effective atremoving or preventing scale formation wherein the scale includescalcium salts, e.g., calcium phosphate, calcium oxalate, calciumcarbonate, calcium bicarbonate or calcium silicate. The scale which isintended to be prevented or removed by the present invention may beformed by any combination of the above-noted ions. For example, thescale may involve a combination of calcium carbonate and calciumbicarbonate.

In some embodiments the water source has a pH of between about 6 andabout 11 prior to treatment using the methods, apparatuses, or systemsof the present invention. In some embodiments, the pH of the watersource prior to treatment is greater than about 8.

In some embodiments, the pH of the water source is raised to greaterthan 9, and in some embodiments the pH is greater than 10 prior totreatment.

Apparatus and Systems

Embodiments of the invention include one or more treatment reservoirsfor contacting a water source with the water treatment agents, includingfirst the resin shedding the threshold agent followed by the insolublemagnesium compound conversion agent. Embodiments of the inventioninclude a system or apparatus having a single treatment reservoir, oneor more treatment reservoirs in parallel and/or one or more treatmentreservoirs in series. In embodiments which include more than onetreatment reservoir, each treatment reservoir may include the same oneor more water treatment agents or may include different one or morewater treatment agents. For example, the water source may be passed overa plurality of reservoirs, in the same or in separate vessels, includingthe same or different water treatment agents, i.e. water treatmentagents in the form of an exhausted ionic resin shedding a conversionagent and/or an insoluble magnesium compound that may be bound to asupporting material. Regardless of the number and/or arrangement oftreatment reservoirs, according to the invention, the water source isfirst treated with the exhausted ionic resin, followed by treatment withthe insoluble magnesium compound.

The treatment reservoir may be any shape or size appropriate for the useof the water and the volume of water to be treated. In some embodiments,the apparatus includes a vessel which includes a treatment reservoir.The treatment reservoir may be contained in a vessel which can be small,such as a canister filter-type vessel as used for small drinkingpurification processes. Alternatively, the vessel can be large, such asa large water treatment tank as used in whole house water softening. Thetreatment reservoir may be for example, a tank, a cartridge, a filterbed of various physical shapes or sizes, or a column. In someembodiments, the treatment reservoir is pressurized. In otherembodiments, the treatment reservoir is not pressurized.

Some embodiments of the invention include a treatment reservoirincluding a water inlet and a water outlet. In some embodiments, thewater may enter and exit the treatment reservoir through the sameopening or channel. In some embodiments, the treatment reservoir iscontained within a vessel. Water to be treated enters the vessel throughan inlet located at or near the top of a vessel, flows downward alongthe vessel wall or walls, and enters the treatment reservoir at thebottom of the vessel. The water flows upward through the treatmentreservoir toward the top of the vessel and exits the vessel through anoutlet at or near the top of the vessel.

An example of a treatment reservoir according to an embodiment of theinvention is shown in FIG. 2, a schematic of a treatment reservoirapparatus of the present invention, shown at reference 10. The apparatusincludes: an inlet 12 for providing the water source to a treatmentreservoir 14; a treatment reservoir 14 including one or more watertreatment agents 16; an outlet 18 for providing treated water from thetreatment reservoir; and a treated water delivery line 20. According topreferred embodiments of the invention, the water treatment agents 16include a first exhausted ionic resin and a second insoluble magnesiumcompound. In some embodiments, the treated water delivery line 20provides water to a selected cleaning device. In some embodiments, thereis no filter between the outlet and the treated water delivery line. Aflow control device 22 such as a valve 24 can be provided in the treatedwater delivery line 20 to control the flow of the treated water into asecond treatment reservoir (not shown in FIG. 2) which then has a secondwater delivery line to provide the water to the selected end use device,e.g., a ware washing machine, a laundry washing machine.

In some embodiments, the entire treatment reservoir can be removable andreplaceable. In other embodiments, the treatment reservoir can beconfigured such that water treatment agents contained within thetreatment reservoir is removable and replaceable (e.g. replace theexhausted ionic resin and/or insoluble magnesium compound bound to asupporting material). In some embodiments, the treatment reservoirincludes a removable, portable, exchangeable cartridge including a watertreatment agent, e.g., magnesium, bound to a supporting material.

Exhausted Ionic Resins

According to embodiments of the invention, an ionic resin is the firstwater treatment agent contacting a water source. The ionic resin used incombination (specifically, followed by treatment with the second watertreatment agent) with the insoluble magnesium compound prevents scaleformation on surfaces contacted by the water treated according to theinvention.

In a further aspect, a substantially water insoluble resin material isprovided, although a variety of resin materials may be used with theapparatuses of the present invention. Further description of waterinsoluble resin materials is disclosed, for example, in U.S. patentapplication Ser. No. 12/764,621, entitled “Methods and Apparatus forControlling Water Hardness,” the entire contents of which are herebyexpressly incorporated herein by reference. In some embodiments, a resinis capable of binding magnesium ions preferentially over binding calciumions. The resin for use as a supporting material can include any ionexchange resin. Preferably, the ion exchange resin is exhausted. Forexample, in some embodiments, the resin includes an acid cation exchangeresin, e.g., a weak acid cation exchange resin, or a strong acid cationexchange resin. In other embodiments, the supporting material is achelating resin. According to a preferred embodiment the resin is anexhausted weak cation exchange resin.

According to the invention, the first water treatment agent sheds athreshold agent into the water source, such as an acrylic acid polymeror methacrylic acid polymer. In some embodiments, the supportingmaterial is not inorganic. In some embodiments, the supporting materialcomprises a polymer having sulfonic acid substituents. For example, insome embodiments, the supporting material does not include a ceramicmaterial, and/or zeolites.

In preferred embodiments, the resin material is an exhausted resinmaterial. As used herein, the term “exhausted resin material” refers toan ion exchange resin material that can control water hardness, but thatis incapable of performing an ion exchange function. In someembodiments, an exhausted resin material has a surface that issubstantially loaded with a plurality of one or more multivalentcations, and is thus unable to exchange ions with a water source whencontacted with a water source. The exhausted resin materials of thepresent invention do not control water hardness through an ion exchangemechanism. That is, the surface of an exhausted resin material is inert,as it is loaded with a plurality of multivalent cations.

The first water treatment agent may include a resin substantially loadedwith a plurality of one or more multivalent cations. As used herein, theterm “multivalent cations” refers to cations having a valency of 2 orhigher. In some embodiments, the multivalent cations include a mixtureof calcium and magnesium ions. The calcium and magnesium ions may beloaded on to the resin material at a ratio of from about 1:10 to about10:1, about 1:5 to about 5:1, about 1:3 to about 3:1, about 1:2 to about2:1, or from about 1:1 of calcium ions to magnesium ions. In someembodiments, the mixture includes a 2:1 ratio of calcium to magnesiumions.

In other aspects, the water treatment agent includes a substantiallywater insoluble resin material, wherein the resin material is loadedwith a plurality of cations. The cations may be selected from the groupconsisting of a source of column 1 a, 2 a or 3 a elements from thePeriodic Table. In some embodiments, the cations do not include calcium.In some embodiments, the cations are selected from the group consistingof hydrogen ions, sodium ions, magnesium ions, aluminum ions, zinc ions,titanium ions, and mixtures thereof. In some embodiments the cations aresubstantially free or free of aluminum. In further embodiments thecations are substantially free or free of zinc. The resins for use inthe present invention may include, or exclude, any one or more than oneof these cations.

In some embodiments, the resin material includes an acid cation exchangeresin. The acid cation exchange resin may include a weak acid cationexchange resin, a strong acid cation exchange resin, and combinationsthereof. Weak acid cation exchange resins suitable for use in thepresent invention include, but are not limited to, a cross-linkedacrylic acid polymer, a cross-linked methacrylic acid polymer, andmixtures thereof. In some embodiments, resin polymers have additionalcopolymers added. The copolymers include but are not limited tobutadiene, ethylene, propylene, acrylonitrile, styrene, vinylidenechloride, vinyl chloride, and derivatives and mixtures thereof. Examplesof commercially available weak acid cation exchange resins areavailable, and include but are not limited to: C-107 available fromPurolite; Amberlite IRC 76 available from Dow; Lewatit CNP 80 WSavailable from Lanxess; and MAC-3 available from Dow.

Without wishing to be bound by any particular theory, it is thought thatin some embodiments, the resin material provides to the water source asubstantially low molecular weight polymer material. In someembodiments, the resin material is an acrylic acid polymer that providesa polyacrylate material having a molecular weight of about 150 to about100,000 to the water source. In other embodiments, the resin materialprovides a polyacrylate material having a relatively low molecularweight of less than about 20,000 to the water source. Additionaldescription of threshold agent shedding from exhausted resins isdisclosed in U.S. patent application Ser. No. 12/764,606, entitled“Catalytic Water Treatment Method and Apparatus” and Ser. No.12/887,775, entitled “In Situ Cleaning System,” the entire contents ofwhich are hereby expressly incorporated herein by reference.

The resin material may be provided in any shape and size, includingbeads, rods, disks or combinations of more than one shape. In someembodiments, the resin material is selected from the group consisting ofa gel type resin structure, a macroporous type resin structure, andcombinations thereof. Without wishing to be bound by any particulartheory it is thought that the resin particle size may affect the abilityof the resin material to control water hardness. For example, in someembodiments, the resin material may have a particle size of from about0.5 mm to about 1.6 mm. In other embodiments, the resin material mayhave a particle size as large of 5.0 mm. The resin material may alsoinclude a mixture of particle sizes, viz. a mixture of large and smallparticles.

Other factors that are thought to have an effect on the ability of theresin material to prevent scaling typically caused by water hardnessinclude, but are not limited to, the particle size distribution, theamount of cross linking, and the polymers used. In some embodiments, theability of the resin material to control water hardness is impacted bywhether there is a narrow particle size distribution, e.g., a uniformitycoefficient of 1.2 or less, or a wide (Gaussian) particle sizedistribution, e.g., a uniformity coefficient of 1.5 to 1.9.

Further, it is thought that the selectivity of the resin can be modifiedto tailor the resin to have an affinity for one ion over another. Forexample, the amount of cross linking and type of polymers included inthe resin are thought to impact the selectivity of the resin. Aselective affinity for particular ions over other ions may be beneficialin situations where a high affinity for certain ions, e.g., copper, maybe damaging, e.g., foul or poison, to the resin itself. The resinmaterial may bind cations by a variety of mechanisms including, but notlimited to, by ionic or electrostatic force.

Preferably, the first water treatment agent is an exhausted ionic resin.However, in some embodiments, the resin may include a weak acid cationexchange resin having H+ ions attached to the active sites, which maythen be exhausted, viz. loaded with a plurality of multivalent cationsby any of a variety of methods, e.g., by having a water source run overit. In some embodiments, the plurality of multivalent cations includes,but is not limited to, the calcium and magnesium present in the watersource. Without wishing to be bound by any particular theory, it isthought that as the water runs over the resin, the calcium and magnesiumions in the water will attach to the resin, thereby neutralizing it. Atthis point the resin is exhausted as it can no longer exchange ions withthe water source. Similar two step or one step processes could be usedto bind other water treatment agents such as aluminum, titanium, zinc,and polymorphs of calcium, to the supporting material for alternativeembodiments of the invention.

As one skilled in the art shall ascertain, the resin may be provided inany shape and size, including beads, sheets, rods, disks or combinationsof more than one shape.

Insoluble Magnesium Compounds

According to embodiments of the invention, a conversion agent, such asan insoluble magnesium compound is the second water treatment agentcontacting a water source. The insoluble magnesium compound used incombination (specifically, contacting water after it is treated with thefirst water treatment agent, i.e. ionic resin) with the ionic resinprevents scale formation on surfaces contacted by the water treatedaccording to the invention. The sequential use of the water treatmentagents further reduces and/or eliminates the deleterious effects ofcementing on the insoluble magnesium compound, such as a magnesium oxidebed, cartridge or other type of container.

An insoluble compound refers to an agent selected for use with themethods of the present invention having a solubility of less than about0.01 g/100 mL in water. In some embodiments, low solubility is preferredfor longer conversion activity. According to an embodiment of theinvention, an insoluble magnesium compound contacts the water treatedwith the threshold agent shed from the exhausted ionic resin of thefirst water treatment agent. The treatment with the insoluble magnesiumcompound is hypothesized, according to one mechanism of action, topromote the precipitate from solution of water hardness ions into a lessthermodynamically favorable form, such as aragonite particles. Withoutwishing to be bound by any particular theory, it is further thought thatthe insoluble magnesium or calcium may be re-dissolved into the treatedwater source, causing an apparent increase in total solubilized waterhardness.

The insoluble magnesium compound as disclosed herein may also bereferred to as a conversion agent and/or catalyst as it may promote suchprecipitation in a treated water source (i.e., precipitate calciumcarbonate out of the water in the form of aragonite). Regardless of themechanism of action of the insoluble magnesium compound contacting thetreated water after the first treatment with the exhausted ionic resinshedding a threshold agent, the second water treatment agent does notresult in the reduction in the solubilized water hardness in the watersource. Unexpectedly there is an increase in solubilized water hardnessand the treated water still exhibits many beneficial effects, includingreducing the scale formation on a surface in contact with the treatedwater source.

The inclusion of the conversion agent, such as the insoluble magnesiumcompound, substantially reduces or eliminates the need to includebuilders in cleaning compositions employing the water treated accordingto the invention. According to an embodiment of the invention, thereduction in hard water scaling is achieved in the absence of builders.According to a further embodiment, cleaning with a composition and thetreated water according to the invention may optionally contain nobuilder, e.g. a detergent free of builder.

According to the invention, the second water treatment agent is a waterinsoluble compound. Insoluble compounds suitable for use as the secondwater treatment agent according to the invention include, but are notlimited to metal oxides, metal hydroxides, polymorphs of calciumcarbonate and combinations and mixtures thereof. In some embodiments,the conversion agent comprises a metal oxide. Metal oxides suitable foruse in the methods of the present invention include, but are not limitedto, magnesium oxide, aluminum oxide, titanium oxide, and combinationsand mixtures thereof. Metal hydroxides suitable for use with the methodsof the present invention include, but are not limited to, magnesiumhydroxide, aluminum hydroxide, titanium hydroxide, and combinations andmixtures thereof. One or more of the aforementioned agents may be used.

In some embodiments, magnesium oxide is used as the second watertreatment agent. In some embodiments, magnesium hydroxide is used as thesecond water treatment agent. In still yet other embodiments, acombination of magnesium oxide and hydroxide are used as the secondwater treatment agent according to the invention. In further embodimentsthe second water treatment agent is substantially free or free ofaluminum.

In further embodiments the second water treatment agent is substantiallyfree or free of zinc.

Supporting Material for Insoluble Magnesium Compounds

In some aspects of the invention, a supporting material is provided forthe insoluble magnesium compound. The supporting material may be anymaterial to which the magnesium compounds can be bound.

In some embodiments, the supporting material has a density slightlyhigher than the density of water to maximize fluidization and/oragitation of the supporting material. In some embodiments, thesupporting material binds cations by ionic or electrostatic force. Insome embodiments, the bound cation is magnesium. In some embodiments,the supporting material is inert. The supporting material may beprovided in any shape and size, including beads, sheets, rods, disks orcombinations of more than one shape.

The magnesium compounds according to the invention do not undergo anionic exchange which would require recharging of magnesium bed,cartridge or other type of container, as in numerous existing watertreatment systems. Rather, the magnesium compound continually promotethe precipitation of calcium carbonate over an extended period of timewithout needing to be replaced for a long time. Water insolublemagnesium compounds as a conversion agent for the treatment of water aredisclosed in further detail in U.S. patent application Ser. No.12/764,606, entitled “Catalytic Water Treatment Method and Apparatus,”Ser. No. 12/114,448, entitled “Water Treatment System and DownstreamCleaning Methods,” and Ser. No. 12/114,513, entitled “CleaningCompositions Containing Water Soluble Magnesium Compound and Method ofUsing Them,” the entire contents of which are hereby expresslyincorporated herein by reference.

Although not intending to be limited to a particular theory of theinvention, as aragonite precipitates on the surface of the second watertreatment agent it is believed to act according to one or more possiblemechanisms of action, which are not intended to limit the scope of theinvention (e.g., promoting precipitation of aragonite and/orsolubilizing magnesium and/or calcium into the water source resulting inincreased water hardness in the water source).

According to the invention, ongoing experiments have shown that thewater treatment agent continues to function after treating 25,000gallons of water per pound of resin without fail. In practice, thelifespan of the resin will depend upon the water conditions and thepresence of contaminants in the water. In average water conditions, theresin may last 1 or 2 years, while in very good water conditions or inlow water usage rates it may last 5 or 10 years.

In some embodiments, water contacted with a water treatment agent formsa precipitate which includes a cation which is different from the watertreatment agent. For example, in some embodiments the water treatmentagent includes a source of magnesium ions and the precipitate formedincludes calcium. In some embodiments, water contacted with a watertreatment agent forms a calcium precipitate. The calcium precipitateformed using the methods of the present invention is such that theprecipitate (e.g. aragonite crystals) flows through the water sourceharmlessly. That is, in some embodiments, unlike conventional watertreatment systems, there is not a need to filter or remove theprecipitate from the treated water.

Methods of Use

In some aspects, the present invention provides methods for reducingand/or controlling scaling formation caused by solubilized waterhardness. In further aspects, the present invention provides methods forreducing and/or eliminating cementing of the second water treatmentagent, namely the insoluble magnesium oxide bed, cartridge or other typeof water treatment container.

According to further aspects of the invention the methods, apparatuses,and systems may be used for a variety of purposes and cleaningapplications. For example, an apparatus for employing the watertreatment methods of the present invention can be connected to the watermain of a house or business. The apparatus may further be employed inline before a hot water heater, or after a hot water heater. Thus, anapparatus of the present invention can be used to reduce scaling onsurfaces contacted and/or treated by water having solubilized waterhardness under a variety of conditions, including for example, in hot,cold and room temperature water sources. In some embodiments, the waterto be treated in accordance with the present invention is at atemperature of between about 10° C. and about 90° C. In someembodiments, the temperature of the water to be treated is above roomtemperature, e.g., greater than about 20° C.

In some aspects, the present invention provides a system for use in acleaning process. The system includes providing a water source to anapparatus for treating the water source. In some embodiments, theapparatus for treating the water source includes a plurality of thefollowing components: (i) an inlet for providing the water source to afirst treatment agent; (ii) a first treatment agent containing an ionicresin(e.g. exhausted ionic resin shedding a threshold agent); (iii) asecond treatment agent containing an insoluble magnesium compound (e.g.magnesium oxide bed) that may be bound to a supporting media and/or anunbound additional functional ingredient; (iv) an outlet for providingtreated water from the series of at least two sequential water treatmentagents; and (v) a treated water delivery line for providing the treatedwater to a cleaning application, such as an automatic washing machine,such as a ware washing machine. In some embodiments, a device, e.g., ascreen, is present in the treatment reservoir(s) in order to keep thewater treatment agent(s) contained within the treatment reservoir as thefluid is passing over or through it. In some embodiments, the apparatusis filter less, with no filter between the outlet and the treated waterdelivery line.

In additional aspects, the methods according to the invention includecontacting a water source with a first water treatment agent, followedby contact the first treated water source with a second water treatmentagent. Preferably, the first water treatment agent is a weak cationexchange resin capable of shedding a threshold and the second watertreatment agent is an insoluble magnesium compound conversion agent,such as a magnesium oxide bed. The step of contacting can include, butis not limited to, running a water source over or through a treatmentreservoir or a plurality of treatment reservoirs housing the first andsecond water treatment agents. The treatment reservoir may house a solidsource, e.g., a column, cartridge, or tank, including the watertreatment agents. The contact time is dependent on a variety of factors,including, for example, the pH of the water source, the hardness of thewater source, and the temperature of the water source.

In some embodiments, the water treatment agent(s) in the treatmentreservoir may be in the form of an agitated bed or column. The bed orcolumn can be agitated by any known method including, for example, bythe flow of water through the column, fluidization, mechanical agitationor mixing, high flow backwash, recirculation, air sparge, eductor flow,and combinations thereof. In some embodiments, there is a fluidized bed,e.g., a column or a cartridge, in the treatment reservoir. Fluidizationis obtained by an increase in the velocity of the fluid, e.g., water,passing through the bed such that it is in excess of the minimumfluidization velocity of the media. Fluidization creates a flowing bedthat is in constant agitation when the water is flowing. In otherembodiments, the conversion agent is agitated using centrifugal forcescreated by tangential water flows, mechanical agitation, or ultrasoundagitation, for example. The agitation ultimately results in a cleaningof the conversion agent, removing the calcium crystals from theconversion agent, such that water can continue to flow over or throughthe media with reduced obstruction.

The methods according to the invention may include the agitation of themagnesium compound, such as the bed or column of magnesium oxide inorder to further aid in avoiding “cementing,” i.e., agglomeration of theparticles from the insoluble magnesium compound with the hardness ionsfrom the water source. Such agitation may prevent the precipitant frombinding and/or may cause precipitated calcium to become dislodged.According to a non-limiting embodiment of the invention, as aragoniteparticles precipitate, agitation results the beads or granules of thesupport media, for example, to bounce into each other and/or to bounceinto the solid, unbound, insoluble magnesium compounds. The physicalimpact knocks off the precipitate, such as aragonite crystals. The loosecalcium carbonate crystals may then pass through and exit the treatmentreservoir along with the treated water. In this way, the agitationcauses it to be self-cleaning, exposing the conversion agent andenabling it to continue nucleating and precipitating the calciumcarbonate from the water source. It has been discovered that thecatalyst, i.e. the conversion agent, according to embodiments of theinvention can continue to perform excellently on very hard water, suchas 17 grain water, even after used to treat water for 900 consecutivedish machine cycles, with the inside of the dish machine remainingnearly perfect, whereas untreated was resulted in heavy scale deposits.

Methods of Cleaning an Object

It is contemplated that the methods of the present invention can be usedin a broad variety of industrial, household, health care, vehicle care,and other such applications. Some examples include surface disinfectant,ware cleaning, laundry cleaning, laundry sanitizing, vehicle cleaning,floor cleaning, surface cleaning, pre-soaks, clean in place, and a broadvariety of other such applications. The methods can reduce any of avariety of detrimental effects of hard water. In an embodiment, themethod can reduce precipitation of calcium salt. In an embodiment, themethod can reduce scaling.

In some aspects, the present invention relates to a method of cleaningan object, comprising contacting the object with a treated water sourceobtained according to the methods of the invention. According to anembodiment of the invention, the methods comprise, consist of and/orconsist essentially of treating a water source with a first watertreatment agent (e.g., an exhausted ionic resin, such as a weak cationexchange resin shedding a threshold agent); treating the water sourcewith a second water treatment agent (e.g., a solid, insoluble magnesiumcompound, such as a magnesium oxide bed); wherein the treating steps mayinclude running the water over the first and second water treatmentagents; contacting an object in need of cleaning with the treated water,such that the solubilized hardness of the water does not cause and/orsubstantially reduces scaling on the treated surface. The methods ofcleaning an object according to the invention may include forming a usesolution with the treated water and a detergent prior to contacting anarticle with the use solution such that the article is cleaned.

The contacting of an article with the treated water source and/or a usesolution can include any of numerous methods for applying a composition,such as spraying the composition, immersing the object in thecomposition, or a combination thereof. The compositions can be appliedin a variety of areas including kitchens, bathrooms, factories,hospitals, dental offices and food plants, and can be applied to avariety of hard surfaces having smooth, irregular or porous topography.The treated water source and/or a use concentration of a composition ofthe present invention can be applied to or brought into contact with anobject by any conventional method or apparatus for applying a cleaningcomposition to an object. For example, the object can be wiped with,sprayed with, and/or immersed in the composition, or a use solution madefrom the composition. The composition can be sprayed, or wiped onto asurface; the composition can be caused to flow over the surface, or thesurface can be dipped into the composition. Contacting can be manual orby machine.

Exemplary articles that can be treated, i.e., cleaned, with the usesolution comprising a detersive composition and treated water include,but are not limited to motor vehicle exteriors, textiles, foodcontacting articles, clean-in-place (CIP) equipment, health caresurfaces and hard surfaces. Exemplary motor vehicle exteriors includecars, trucks, trailers, buses, etc. that are commonly washed incommercial vehicle washing facilities. Exemplary textiles include, butare not limited to, those textiles that generally are considered withinthe term “laundry” and include clothes, towels, sheets, etc. Inaddition, textiles include curtains. Exemplary food contacting articlesinclude, but are not limited to, dishes, glasses, eating utensils,bowls, cooking articles, food storage articles, etc. Exemplary CIPequipment includes, but is not limited to, pipes, tanks, heatexchangers, valves, distribution circuits, pumps, etc. Exemplary healthcare surfaces include, but are not limited to, surfaces of medical ordental devices or instruments. Exemplary hard surfaces include, but arenot limited to, floors, counters, glass, walls, etc. Hard surfaces canalso include the inside of dish machines, and laundry machines. Ingeneral, hard surfaces can include those surfaces commonly referred toin the cleaning industry as environmental surfaces. Such hard surfacescan be made from a variety of materials including, for example, ceramic,metal, glass, wood or hard plastic.

In some embodiments, the water treatment methods and systems of thepresent invention can be applied at the point of use. That is, a watertreatment method, system, or apparatus of the present invention can beapplied to a water source upstream of an application such as a washingsystem. In some embodiments this provides methods of in situ watertreatment capable of reducing hard water scaling on treated objectswithout reducing the solubilized water hardness of a water source. Infurther embodiments, the water treatment is applied immediately prior tothe desired end use of the water source. For example, an apparatus ofthe present invention could be employed to a water line connected to ahousehold or restaurant appliance, e.g., a coffee maker, an espressomachine, an ice machine. An apparatus employing the methods of thepresent invention may be located in a washing system. For example, itcan also be included as part of an appliance which uses a water source,e.g., a water treatment system built into an automatic or manual washingsystem, a coffee maker, an ice machine, or any other system which maybenefit from the use of treated water.

Additionally, an apparatus for employing the water treatment methods ofthe present invention can be connected to the water main of a house orbusiness. The apparatus can be employed in line before the hot waterheater, or after the hot water heater. Thus, an apparatus of the presentinvention can be used to reduce solubilized water hardness in hot, coldand room temperature water sources.

Because the embodiments of the invention are so useful at reducingand/or eliminating hard water scaling of an object and/or on a surfacecontacted with a treated water source having solubilized hardness fromwater (including according to some embodiments increased solubilizedwater hardness), treated water may be used with detergents havingreduced amounts of builders or that are low in builders. In someembodiments, the treated water may be used with detergents which aresubstantially free of builders. In some embodiments, the treated watermay be used with detergents which are substantially free of chelant,builder, threshold agent, sequestrant or combinations thereof. Besidesbeing economically advantageous, the use of low builder detergents or nobuilder detergents allowed by embodiments of the invention is also morebeneficial to the environment, as is the elimination of the need toregenerate the system such as by using sodium chloride.

All publications and patent applications in this specification areindicative of the level of ordinary skill in the art to which thisinvention pertains. All publications and patent applications are hereinincorporated by reference to the same extent as if each individualpublication or patent application was specifically and individuallyindicated by reference.

EXAMPLES

Embodiments of the present invention are further defined in thefollowing non-limiting Examples. It should be understood that theseExamples, while indicating certain embodiments of the invention, aregiven by way of illustration only. From the above discussion and theseExamples, one skilled in the art can ascertain the essentialcharacteristics of this invention, and without departing from the spiritand scope thereof, can make various changes and modifications of theembodiments of the invention to adapt it to various usages andconditions. Thus, various modifications of the embodiments of theinvention, in addition to those shown and described herein, will beapparent to those skilled in the art from the foregoing description.Such modifications are also intended to fall within the scope of theappended claims.

Example 1 Effect of Flow Sequence on Synergy Between Magnesium Oxide andWeak Acid Cation Exchange Resin

A MgO bed was prepared by placing 100 g magnesium oxide in achromatography column and rinsing it with 1 gallon of deionized water toremove any fine particulate. A resin bed was prepared using 100 g ofAmberlite IRC76 resin which had been previously flushed with 17 grainwater hardness until the cation exchange capability had been exhausted.Amberlite IRC76 is a weak cation exchange resin (commercially availablefrom Dow Chemical).

An aliquot of 250 mL 17 grain water was eluted first through the MgO bedfollowed by the resin bed. A second aliquot was first eluted through theresin bed followed by the MgO bed. Third and fourth aliquots were elutedthrough each bed alone.

A new bed was prepared by premixing 50 g of the MgO and 50 g of theresin (“mixed bed”). Analysis of the resulting effluents showed quitedifferent results depending on the order of elution through the columns.The columns were also allowed to stand overnight under an additionalcharge of 17 grain water (to check for cementing) with quite unexpectedresults, shown in Table 1.

TABLE 1 Effluent Properties Hardness Column 1st Step 2nd Step AppearancepH (Grains) Cemented MgO resin hazy 9.89 17 Yes resin MgO clear 9.55 42No resin none clear 8.82 17 No MgO none clear 8.41 32 Yes mixed nonehazy 9.87 30 Yes

The effluent coming through the sequence of resin followed by MgO wasresistant to column cementing but also had solubilized what is presumedto be Mg from the MgO or Ca solubilized from a calcium carbonatecrystals growing on the column, which led us to suspect that it might besuperior in resisting cementing. However, the effluent that went throughthe MgO column first did in fact cement the MgO system and showed noenrichment in magnesium. Similar performance to the MgO first system wasnoted for the MgO alone and the mixed media tests. The resin alone, asexpected did not cement, but showed no enrichment in water hardness.

The results of Table 1 show that only the sequential treatment usingfirst a resin water treatment agent, followed by a magnesium oxidecolumn, produced clear treated water without cementing the magnesiumoxide column. Unexpectedly the “mixed” column resulted in an increasedamount of solubilized water hardness (42 grains) compared to the initialwater hardness (17 grain). This unexpected increase in water hardness,without the result of hazy treated water (resulting in scaling ontreated surfaces), is likely a result of magnesium or calciumsolubilized from the insoluble magnesium oxide column added to the watersource.

Example 2 Effect of Elution Order on Scale Mitigation of Magnesium Oxideand Weak Acid Cation Exchange Resin

A 200 cycle scaling test was run using treated 17 grain water (i.e. hardwater) on glasses in a dish machine, using cartridges of MgO and/orAmberlite IRC76 resin set-up in sequences mirroring those described inExample 1.

As shown in FIG. 1, the combination of the water running through theresin first followed by the MgO gave significantly reduced scaling onthe treated glasses. The results show that the combination of watertreated through the resin following by the MgO column was superior toeither system alone, to the MgO first followed by the resin, or to the“mixed” media.

The inventions being thus described, it will be obvious that the samemay be varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the inventions and all suchmodifications are intended to be included within the scope of thefollowing claims.

1: An apparatus for treating a water source for use in a cleaningapplication comprising: (a) an inlet for providing a water source to afirst treatment reservoir; (b) one or more treatment reservoirs housing(1) a first water treatment agent, wherein said first water treatmentagent is an exhausted ionic resin that is incapable of performing ionexchange followed by (2) a second water treatment agent consisting of ametal oxide and/or hydroxide compound, wherein the first water treatmentagent sheds a threshold agent; (c) an outlet for providing treated waterfrom the one or more treatment reservoirs; and (d) a treated waterdelivery line for providing the treated water to a cleaning application,wherein the solubilized water hardness in the treated water source doesnot result in hard water scaling. 2: The apparatus of claim 1, whereinthe metal oxide and/or hydroxide is selected from the group consistingof insoluble metal oxides, insoluble metal hydroxides and combinationsthereof. 3: The apparatus of claim 2, wherein the metal oxide and/orhydroxide is selected from the group consisting of magnesium oxide,magnesium hydroxide, aluminum oxide, aluminum hydroxide, titanium oxide,titanium hydroxide and combinations thereof. 4: The apparatus of claim1, wherein the ionic resin is a weak cation exchange resin selected fromthe group consisting of a gel type resin structure, a macroporous typeresin structure, and combinations thereof, and wherein the resin sheds athreshold agent selected from the group consisting of an acrylic acidpolymer, a methacrylic acid polymer and combinations thereof. 5: Theapparatus of claim 1, wherein there is no filter between the treatmentreservoirs and/or the outlet and the treated water delivery line. 6: Theapparatus of claim 1, wherein one or more of the treatment reservoirscomprise a portable, removable cartridge. 7: The apparatus of claim 1,wherein the metal oxide and/or hydroxide is contained in a column, bed,or other type of container housed within a treatment reservoir and thecontainer is agitated by a method selected from the group consisting ofthe flow of water through the container, by fluidization, mechanicalagitation, high flow backwash, recirculation, and combinations thereof.8: The apparatus of claim 1, wherein the second water treatment agentdoes not cement. 9: The apparatus of claim 1, wherein the metal oxideand/or hydroxide compound is insoluble in water. 10: The apparatus ofclaim 1, wherein the exhausted ionic resin is a weak cation exchangeresin that is loaded with a plurality of one or more multivalentcations. 11: The apparatus of claim 10, wherein the cation exchangeresin is substantially water insoluble. 12: The apparatus of claim 11,wherein the threshold agent is an acrylic acid polymer, a methacrylicacid polymer or combinations thereof. 13: The apparatus of claim 1,wherein the solubilized water hardness is increased in the treated watersource and results in greater reduction of hard water scaling that useof an ionic resin water treatment agent or metal oxide and/or hydroxidecompound water treatment agent alone. 14: An apparatus for treating awater source to clean an article comprising: (a) an inlet for providinga water source to a first treatment reservoir; (b) one or more treatmentreservoirs housing (1) a first water treatment agent comprising asubstantially water insoluble ionic resin, wherein said ionic resin isexhausted so that it is incapable of performing ion exchange; followedby (2) a second water treatment agent consisting of a metal oxide and/orhydroxide compound, wherein the first water treatment agent sheds athreshold agent; (c) an outlet for providing treated water from the oneor more treatment reservoirs; and (d) a treated water delivery line forproviding the treated water to a cleaning application, wherein thesolubilized water hardness in the treated water source does not resultin hard water scaling. 15: The apparatus of claim 15, wherein the ionicresin is a weak cation exchange resin loaded with a plurality of one ormore multivalent cations and wherein the metal oxide and/or hydroxide isselected from the group consisting of magnesium oxide, magnesiumhydroxide, aluminum oxide, aluminum hydroxide, titanium oxide, titaniumhydroxide, and mixtures thereof. 16: The apparatus of claim 15, whereinthe metal oxide and/or hydroxide is a magnesium oxide bed, cartridge orother type of container.